Format obsolescence: assessing the threat and the defenses

This paper aims to examine the approach to format obsolescence, preparing for format migration, that has guided most digital preservation work for the last 15 years. It asks why this approach has not rescued significant content in that time, and whether it would succeed in rescuing future content at risk of format obsolescence.

The paper examines the mechanisms of format obsolescence, its historical and current incidence, and identifies attributes of at‐risk formats. It examines each step of the current approach asking how effective it would be for these formats.

The current approach assumes format obsolescence is common, happening frequently to most formats. In fact it is rare, happening infrequently to rare formats. The current approach, based on this mis‐diagnosis, is ineffective. An alternate approach, based on open source and virtualization, is cheaper and more effective.

The paper makes the case that the commonly accepted approach to digital preservation devotes resources to activities that are unlikely to be effective.